What moves the result most
Over a few years, the monthly deposit matters far more than the interest rate. $200 a month for 5 years is $12,000 paid in; at 4% a year it grows to about $13,300, so interest adds around $1,300. Doubling the deposit adds about $13,300 more; doubling the rate to 8% adds only about $1,500. Rates start to matter over long periods, which is why starting early helps.
Which rate to enter
Use the rate your account actually pays today, before tax: the APY shown by your bank or savings account. Savings rates change often, and variable rates can fall, so re-run the calculation when your rate changes. Don't enter stock-market returns here: shares don't pay a fixed rate and can fall.
Make the plan hold
- Pay yourself first: set the transfer for the day after payday, not the end of the month.
- Give the money a name: a goal with an amount and a date ("car, $6,000, June") is easier to keep than "savings".
- Protect it: keep it separate from your everyday account, in an account covered by deposit insurance (FDIC or NCUA in the US, FSCS in the UK).
Read the full guide: how to save money, and how much to save each month. If you don't have a safety net yet, start with the emergency fund calculator.
About this calculator
Deposits are counted at the start of each month and interest is compounded monthly. Real accounts may credit interest daily, monthly or yearly, and interest may be taxed, so treat the result as an estimate. Nothing you type leaves your browser.
Frequently asked questions
Is interest compounded in this calculator?
Yes, monthly: each month's interest earns interest the following month. Your bank's method may differ slightly, which changes the result by a few dollars, not the overall picture.
How long will it take to save $10,000?
At $200 a month with no interest, 50 months. Enter your own figures and a $10,000 goal to see the exact month with your rate.
Should I include my salary increases?
Not in the base plan. Run it with today's deposit, then raise the monthly amount when your pay goes up: it's the fastest way to finish early.